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(No Model.) 4 Sheets-Sheet 1.-

J. E. MITCHELL. SIFTING MACHINE.

Patented Oct. 6, 189.6.

3* I Q 1 v 5 M46 INVENTOB- ATTORNEYS.

(No Model.) 4 Sheets-Sheet 2.

J. E. MITCHELL.

SIPTING MACHINE. 7 No. 568,915. Patented Oct; 6, 1896.

WITNIESES. WM INVENTOR. M 4 M ATTORNEYS:

m: umuus Prrzns ca. PHOTB-LHHQ. wnsmuamu. n. c.

Sheet 3.

4 Sheets (No Model.)

J. E. MITCHELL.

SITTING MACHINE.

'INVENTOR.

ATTORNEYS.

&7////////////////////////IZ 7/? Patented Oct. 6, 1896.

In: "oaks mans co. M'rcruma, wlsumarou. n. c.

UNITED STATES PATENT OFFICE.

JOHN E. MITCHELL, OF JACKSON, MICHIGAN, ASSIGNOR TO THE HARMONMANUFACTURING COMPANY, OF SAME PLACE.

SIFTING M ACHlNE.

SPECIFICATION forming part of Letters Patent No. 568,915, dated October6, 1896. Application fil d November 12, 1895 Serial No. 568,674. (Nomodel.)

To all whom it natty concern:

Be it known that 1, JOHN E. MITCHELL, a

citizen of the United States, residing at Jackson, in the county ofJackson and State of Michigan, have invented a new and usefulImprovement in Sifting-Machines, of which the following is aspecification.

This invention relates to a sifting-machine in which a horizontal sieveis .employed, and has the object to produce a machine which is simple inconstruction, which has a large sifting capacity, and in which thedirection of the fiow of the material over a sifting or other surfacecan be readily controlled, as desired.

In the accompanying drawings, consisting of four sheets, Figure 1 is aside elevation of my improved sifting-machine. Fig. 2 is a top plan viewthereof with the cover of one of the sieves removed. Fig. 3 is alongitudinal section in line 3 3, Fig. 2. Fig. at is a verticalcross-section in line 4: 4, Fig. 2. Fig. 5 is a fragmentary perspectiveview of one of the propelling-rods and connecting parts. Fig. 6 is afragmentary transverse'elevation, partly in section, showing a modifiedmeans for connecting the sieve-frame with the actuating-shaft. Fig. 7 isa vertical section in line 7 7, Fig. (3. Fig. Sis a cross-section of thesieve-frame and sieve, showing wire-netting arranged over the sieve.Fig. 9 is a top plan view thereof. Fig. 10 is a cross-section showingthe wire-netting mounted in a vertically-adjustable frame.

Like letters of reference refer to like parts in the several figures.

A represents the horizontal box or frame in which the sieve a isarranged and which is provided over the head portion of the sieve' witha flexible feed-spout a and at the opposite end of the sieve with adischarge-spout a for the tailings.

B represents the cover of the sieve-frame,

which is arranged at such a height above the tions 1) for affordingaccess to the sieve when required. 7

0 represents the tight conveyer bottom of the sieve-frame, which isarranged horizon- ;tally like the sieve and provided underneath the endportions of the sieve with dischargespouts cc, through either or both ofwhich the fine material which has passed through the sieve and fallenupon this bottom can be discharged.

The sieve-frame has a vertical and longitudinal gyratory motion or amotion in which each part of the sieve-frame and sieve moves in a circlein a vertical plane lengthwise of the sieve. This motion is imparted tothe sieve-frame by two horizontal shafts d, arranged transverselyunderneath the sieveframe, one behind the other, and provided each withan eccentric D, engaging against the lower portion of a strap or hearingD, secured to the bottom of the sieve-frame. The shafts cl are journaledin two side frames E E.

In order to relieve the driving mechanism of the greater portion of theweight of the sieveframe and connecting parts, two similar sieveframesare arranged side by side, as shown in Figs. 1, 2, and at, and connectedas follows: The eccentrics D underneath one sieve-frame are arranged onthe shafts d diametrically opposite the eccentrics underneath the othersieve-frame, as shown in Fig. 4, so that one sieve-frame is in itshighest position when the other is in its lowest position, and thesieveframes are supported upon a balancing-lever F, which is supportedcentrally upon the sup- I porting framework of the machine and engageswith its ends underneath the sieveframes. "As shown in the drawings, thesupporting-leverF is provided at its middle with a spherical knuckle f,which rests in a socket f, supported by a vertical adjusting-screw fupon a cross piece f connecting the side frames E. I he supporting-leveris provided at its ends with spherical knuckles g, upon which thesieve-frames rest by socket- 5 pieces g, secured to the bottoms of thesieveframes. The weight of one sieve-frame balances the weight of theother by means of this supporting-lever, and the shafts, eccentrics, andstraps are thereby to a large extent relieved of this weight, wherebyexcessive friction and vibrations are avoided. By adjusting the centralsocket of the supportinglever both sieve-frames are simultaneouslyadjusted, and all four eccentric-straps are also simultaneouslyadjusted, so that this single adjustment of thesupportil'ig-levereffectsthe adjustment of both sieve-frames and allfour eccentrics.

H represents the driving-belt, which runs over two pulleys h, mountedcentrally upon the two shafts d, and also over a guide-pulley h if themachineis driven from below, as shown. The two shafts dare connected torotate in unison by cranks i and parallel rods 'i', arranged at the endsof the shafts, the cranks on one side of the machine being arrangeddiametrically opposite the cranks on the other side.

The driving-shafts d may be provided with cranks j, engaging independing bearings for actuating the sieve-frames, as shown in Figs. 6and 7, instead'of eccentrics and straps, if preferred.

When the driving-shafts d are rotated in the direction of the arrow 1 inFig. 3, the upper half of the gyrat-ory movement of the sieve-frametakesplace in a direction away from the feed-spout a, as indicated by thearrow 2, and the lower half of the gyratory V movement takes place in adirection toward the feed-spout, as indicated by the arrow 3. Thematerial resting upon the sieve and upon the tight bottom underneath thesieve is propelled over these surfaces by this gyratory movement in thedirection in which the lower half of the gyrating movement takes place,that is to say, toward the feed-spout or head of the machine. In orderto cause the material to travel in the opposite direction, that is tosay, in the direction in which the upper half of the gyrating movementtakes place, or away from the feedspout, propelling devices are arrangedabove the surface over which the material travels and in proximitythereto. These propelling devices may be constructed in various ways andforms. For instance, they may consist of wires or rods k, which arearranged transversely above the sievesurface or the tight bottomunderneath the sieve-surface and in such proximity thereto as to operateupon the material resting on the sieve or other surface, as shown inFig. 3, or they may consist .of a coarse wire-netting 7c, arranged inthe same way, as shown in Figs. 8, 9, and 10. These propelling devicescompel the material to flow in the direction in which the upper half ofthe gyratory movement takes place and prevent the material fromfollowing the lower half of the gyratory movement, which the materialwould follow in the absence of these devices. hen these propellingdevices are raised so high above the surface on which the material reststhat they have no effect upon the material, the latter flows in thedirection of the lower half of the gyratory movement. It is thereforedesirable to make these propelling devices vertically adjustablewhenthey are used with surfaces over which the material should flowsometimes in one and sometimes in the opposite direction, as, forinstance, the tight conveyer-bottom underneath the sieve. When thetransverse rods or wires are used, each wire can be made individuallyadjustable. by bending the rod or wire in the form of a crank-shaft, andjournaling the crank portions Zin the sides of the sieve-frame andproviding the outer end with an arm or hand-crank Z, by which the wirecan be turned for raising and lowering it. When this hand-crank projectsupwardly, as shown in Fig. 5, the wire is in its lowest positionnearestthe surface over which it is arrangedl By turning the hand-crankdown, the wire is raised to its inoperative position, as shown indot-ted lines in Fig. 5. The wire is held in its various positions by acatch-plate which is provided with depressions or notches," as shown,for holding the hand-crank in its upper and lower positions, and also atslightly diiferent heights above the sieve or other surface, wherebytheintensity of the propelling effect can be modified.

When the wire-netting k is employed, it can be made adjustable bymounting it in a frame 177, orin several frames, which are connectedwith the sieve-frame by cranks n and adjusted by hand-cranks 'n, asshown in Fig. 10.

As shown in Fig. 3, the propelling devices above the sieve are arrangedin their operative position above the sieve-surface and the material ispropelled over the sieve from the feed-spout to the tail end in thedirection of the arrow 4. The propelling devices above the tight bottomare adjusted at two different heights, those over the front portion ofthe tight bottom being raised to their inactive position and those overthe rear portion being in their low or operative position. The materialwhich falls upon the tight bottom, therefore, is divided into twostreams which move in opposite directions, that which falls upon thefront portion of the tight bottom moving toward the head of thesieve-frame, as indicated by the arrow 5, and being discharged by thespout c, and that which falls upon the rear portion of the tight bottombeing propelled toward the tail end of the sieve,

as indicated by the arrow 6, and being discharged through the spout c.The control which is so obtained over the direction of the flow of thematerial on the tight-bottom permits the sifted material to be out 01fat any point and to be directed to separate dischargespouts.

The propelling devices over the sieve do not only serve to direct theflow of the material, but they also serve to agitate the material andincrease the sifting capacity. In the operation of the machine thematerial flowing over the sieveis quickly separated by reason of thevertical tossing movement, according to the size and specific gravitiesof the constituents. Y Vhen the machine is used for separating middlingsfrom bran, the heavy and fine constituents, such as middlings and flour,quickly assume a position nearest the sieve, and the light and largeconstituents, such as bran, &c., float upon the heavy constituents,thereby causing the fine and heavy constituents of the mixture ofmaterial to reach the sieve quickly and pass through the meshes. As anillustration it may be stated that for separating middlings from bran inv the operation which is ordinarily called scalping with a sieve havinga gyratory motion in circles of four inches in diameter and making aboutone hundred and sixty turns per minute, the propelling devices willreverse the flow of the material if said devices are arranged from aboutone-fourth to onehalf of an inch above the surface over which thematerial flows, and will not affect the flow of the material if they arearranged about two inches above such surface.

The sieve is preferably provided with cleaning-balls 0, of rubber orother suitable material, which are arranged below the sieve andsupported in such proximity to the under side of the sieve that thedancing or jumping motion of the balls will cause the same to strikeagainst the under side of the sieve and dislodge any material which mayadhere thereto. As shown in the drawings, these balls are supported uponthe tight bottom underneath the sieve, and each ball is confined to acertain portion of the sieve by cross rods or wires 19, which arearranged between the sieve and the bottom so closely together that theball cannot pass beyond them, while they permit the material to passwithout obstruction.

I claim as my invention-- 1. In a separating-machine, the combinationwith a frame having a substantially horizontal sieve or other surfaceupon which the material rests, of means whereby a vertical longitudinalgyratory motion is imparted to said frame, and stationary propellingdevices arranged above said surface and held in such proximity theretoas to be embedded, wholly or partially, in the material flowing oversaid surface, whereby the material is propelled over the surface in adirection contrary to that in which the lower half of the'gyratorymovement is performed and in which the material would be propelled inthe absence of said propelling devices, substantially as set forth.

2. The combination with a frame having a vertical longitudinal gyratorymotion and containing a horizontal surface over which the materialflows, of propelling devices arranged above said surface and madeadjustable toward and from the same, whereby said propelling devices canbe placed in proximity in which they allow the material to be pro pelledin the opposite direction, substantially as set forth.

3. The combination with a frame having a vertical longitudinal gyratorymotion, of a horizontal sieve and a conveyer-bottom arranged in saidframe, discharge-spouts connected with said bottom, and propellingdevices arranged above said bottom and made adjustable toward and fromthe same,whereby the material falling upon said bottom can be caused toflow in opposite directions, substantially as set forth.

4:. The combination with a frame having a vertical longitudinal gyratorymotion and containing a horizontal surface over which the materialflows, of transverse crank-rods journaled in said frame above saidsurface and means whereby said rods can be secured in their adjustedposition, substantially as set forth.

5. The combination with two sieve-frames arranged side by side, andmeans whereby a vertical longitudinal gyratory motion in oppositedirections is imparted to said frames, of a transverse equalizing-leveron which said frames are supported, substantially as set forth.

6. The combination with two sieve-frames arranged side by side and meanswhereby a vertical longitudinal gyratory motion in opposite directionsis imparted to said frames, of a transverse equalizing-lever on whichsaid frames rest, and a pivotal support for said lever capable ofvertical adjustment, substantially as set forth.

7. The combination with two sieve-frames arranged side by side and meanswhereby a vertical longitudinal gyratory motion in opposite directionsis imparted to said frames, of a transverse equalizing-lever providedwith knuckles at its middle and at its ends, socketpieces secured tosaid frames and resting on the end knuckles of said lever, and asupporting-socket in which the pivotal knuckle of said lever rests,substantially as set forth.

8. The combination with two sieve-frames arranged side by side, oftransverse crankshafts arranged underneath said frames, bearings securedto said frames and engaging with the cranks of said shaft-s, atransverse equalizing-lever on which said framesrest, and avertically-adjustable pivotal support for said lever, substantially asset forth.

Witness my hand this 7th day of November, 1895.

JOHN E. MITCHELL.

Witnesses M. HARMoN, S. B. COLLINS.

